Some of the best communities (/AskHistorians and /AskScience) are already struggling with this. A mod from /AskHistorians:
https://np.reddit.com/r/IAmA/comments/3cxedn/i_am_steve_huff...
>To illustrate, without in any way intending to boast, it is clear that a number of current and past staff members at Reddit really enjoy AskHistorians. This has been made publicly clear a number of times. But the reality of Reddit is that AskHistorians was created by going against the grain, by struggling against Reddit's mechanisms rather than being organically created by them, and by quite frankly disregarding a number of statements about Reddit's underlying philosophy made by admins and CEOs alike. That mostly involves deleting an enormous quantity of comments, with the express purpose that they are not seen any more, that they are vanished into the aether.
>In addition, reddit's increasingly poor reputation on the internet might, for some people, be because of what they perceive as censorship. But in my experience, the majority of that poor reputation is garnered from the kind of communities that Reddit harbours, which have grown larger and increasingly restive. And so long as they're there and doing their thing we have to share a website with them. We have to share a website with communities that have racist slurs in their name, that spew raw bigotry like it's water for all the farms of China. A lot of our flaired users on AskHistorians are professionals in their fields, and at times it is pretty hard to keep convincing them to stay on a website like this. Most of that convincing consists of how much stuff we are able to keep out of our community. I don't see how that is remotely tenable if we're no longer able to actually leave seas of [deleted]